Mixed paving material such as bituminous slurry is used for high quality paving surfaces for roads, parking lots and other surfaces. The production of bituminous slurry, as with many paving materials, requires the mixture of several ingredients. The quality of the bituminous slurry or other paving material is directly dependent on the relative amounts of these ingredients. Prior paving systems for applying paving material to a surface include producing paving material in a hot mix plant and transporting the paving material to the surface to be paved. Another prior paving system includes a mobile paving system that produces and applies paving material as the paving system proceeds down the surface to be paved. One such monitored mobile paving system is disclosed in U.S. Pat. No. 5,044,819 entitled "Monitored Paving System."
It is important with respect to a mobile paving system for an operator to apply a uniform paving surface over the duration of a project. One problem encountered is the difficulty in accurately measuring the weight of aggregate being added to the mix in producing the paving material. The aggregate commonly contains moisture such that the total weight of the aggregate includes some water weight. This amount of moisture is often referred to as the "percent moisture" of the aggregate which means that water makes up the given percent of the total weight of the aggregate.
Some prior paving systems have used a scale for weighing the aggregate as it is transported to a mixer prior to being mixed with other ingredients to produce the paving material. The monitored paving system of U.S. Pat. No. 5,044,819 includes such a scale. However, this prior paving system did not include measurement of moisture in the aggregate.
A moisture sensor for measuring the percent moisture of aggregate called the AQUALIZER.TM. MOISTURE SENSOR is commercially available from CEDARAPIDS.RTM./STANDARD HAVENS.RTM.. This moisture sensor is used in hot mix plants to measure the percent moisture of aggregate after the aggregate leaves an aggregate hopper on its way to be mixed to form the paving material. This moisture sensor shines infrared light on the aggregate and analyzes the resulting reflected light to determine the percent moisture of the aggregate.